1. Field of the Invention
The present invention relates to valves for controlling the flow of a fluid. More particularly, the present invention relates to apparatus and methods whereby oil is separated from water. In particular, the present invention relates to a valve assembly which allows the flow of water while blocking the flow of oil.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Water retention vaults find a wide variety of applications. These water retention vaults are often used so as to collect water from a runoff or drainage. The water retention vault is intended to serve to separate contaminants prior to passing the water back into the municipal sewage system. Various water retention vaults have been constructed having oil-separating properties, debris-separating properties, and particulate-separating properties. In particular, water retention vaults have found wide application in fields such as car washes, mechanical washing systems, helicopter an airplane washing, gasoline station cleaning, and parking lot cleaning.
In these various washing operations, such as those systems used to wash trucks, automobiles, helicopters and airplanes, a great amount of water is wasted when the wash and rinse water is not collected and cleaned for reuse. Further, in addition to water costs, without a water recycle system, additional expense is incurred in city or county water treatment and sewer system bills. When washing such vehicles, the water used in the wash collects hydrocarbons originating from petroleum distillates. Water recycle systems of the prior art have not demonstrated an adequate facility for removing these hydrocarbons from the recycled water. Additionally, in those prior art systems in which oil is effectively separated from the water, these systems tend to be very expensive, complex, and require a great deal of maintenance and repair.
Large spills of oil can also flow into storm drains, such as from loading docks, gas stations, and the like. In addition, quantities of oil and other hydrocarbons are frequently spilled on the ground and subsequent water flow, such as from rain, can cause the oil to flow into storm drains. This is often referred to as “non-point-source pollution”. The volume of oil from non-point-source pollution in typical water runoff is surprisingly large. Studies of shown that if one meter of rain per year falls on a street ten meters wide, then at the observed mean rate, the annual runoff from each kilometer of street will contain about 275 liters of hydrocarbons. Other studies of non-point-source pollution have measured oil concentrations an order of magnitude higher at some locations. Spills can increase the volume of oil even more. The result of these problems include enormous annual cost, both financial and environmental, for containing and treating these waters.
Some known systems have used a screen-type filter through which the water runoff passes. However, such systems are prone to becoming clogged with debris, thereby blocking the inlet to the storm drain. Also, such systems can only collect limited amounts of oil. Other known systems use oil-absorbing materials, particularly cellulose-based materials, that can collect oil. However, those materials permit leaching of the absorbed oil back into the runoff water, because the absorbed oil is not encapsulated in the oil-absorbent material. In addition, these materials typically have small pores so as to create a blocking effect that prevents long-term effectiveness in absorbing oil and limits the quantity of water runoff the can be passed through the materials. Other known systems are available for screening of oil runoff below grade, such as in catchbasins. As such, a need has developed so as to provide a water retention system which can effectively prevent oil from passing from the tank to the sewage system or other water processing facility.
In various washing facilities, the operators are heavily fined if a significant amount of oil or other hydrocarbons passes with the water flow to the sewage system. These fines can often work disadvantageously to the profitability of such washing facilities. As such, it is important to provide a system for preventing the flow of oil outwardly of the water retention tank and into the sewer system.
In the past, various patents have issued relative to systems for capturing oil from water runoff. For example, U.S. Pat. No. 5,350,527, issued on Sep. 27, 1994 to J. C. Kitko, shows a system and process for separating impurities, such as grease, fuels and solid particulate matter from water contaminated therewith. The system comprises passing the water to be treated through a first cleanable strainer bag assembly for filtering solids, a holding/settling tank for separating an oily and water phase and for the precipitation of solids, a second cleanable strainer bag assembly having at least one strainer bag of a porosity finer than the porosity of the strainer bag of the first cleanable strainer bag assembly, a heavy oil gravity separator, a light oil coalescer, a further oil and petrochemical and very fine solid separator with a replaceable polypropylene element for adsorbing or absorbing oil and filtering solids.
U.S. Pat. No. 5,445,730, issued on Aug. 29, 1995 to H. J. Pattee, shows a grease/oil/water separator device and assembly for a vehicle water system having a tank that has three tank compartments. A settling tank is provided with entrance and exit piping such that a diagonal cross-flow of water allow sludge and debris to fall to the bottom of the settling tank. Water enters a trap tank from the settling tank. The trap tank is provided with entrance and exit piping such that a diagonal cross-flow of water is created so as to allow oil and grease to be separated from the water with the exit piping being located at the bottom of the trap tank. The water then enters a pump tank where the grease- and oil-separated water is pumped into a sand filter so as to further filter the water.
U.S. Pat. No. 6,077,423, issued on Jun. 20, 2002 to Roy et al., teaches an above-grade automatic stormwater separation filtration system. The system includes collecting the runoff in a basin and allowing the runoff to settle in the basin for a predetermined time before allowing the filtration step to be initiated. The time delay is controlled by a controller sensitive to rainfall, turbidity, or other variables selected by the user. During the filtration step, a separator member is positioned floatingly between a filter element and impurities floating on the surface of the unfiltered water.
U.S. Pat. No. 6,106,707, issued on Aug. 22, 2000 to Morris et al., describes a modular insert for a curb-inlet storm drain so as to collect trash, oil and other related chemicals. A hopper contains a multitude of irregular, macroscopic fragments of a hydrophobic, compliant, oil-absorbent, copolymer material having a high surface area. The fragments absorb and retain permanently a high quantity of oil and other chemicals passing through the hopper while permitting a high water flow-through rate. The fragments are held in place by a removable bottom plate which allows replacement of the filtering fragments. Trash and debris is collected in an internal basket.
U.S. Pat. No. 6,171,507, issued on Jan. 9, 2001 to Roy et al., provides a method and system for treating storm water runoff containing impurities. This method and system includes collecting the runoff in a basin and allowing the runoff to settle in the basin for a predetermined time before allowing the filtration step to be initiated. The time delay is controlled by a controller sensitive to rainfall, turbidity, or other variables selected by the user. During the filtration step, a separator member is positioned floatingly between a filter element and impurities floating on the surface of the unfiltered water.
U.S. Pat. No. 6,287,459, issued on Sep. 11, 2001 to J. K. Williamson, shows a drainwater treatment system for use in a vertical passageway. This drainwater treatment system includes a catch basin for accepting drainwater which flows downwardly into the drainage system and a filter-supporting section disposed alongside the catch basin. The filter-supporting section accepts drainwater which flows therein from the catch basin and permits drainwater to flow downwardly therethrough. The first and second filters contain a hydrophobic material positioned within the filter-supporting section for filtering contaminants from the drainwater flowing downwardly therethrough. An overflow is associated with the catch basin.
U.S. Pat. No. 6,315,897, issued on Nov. 13, 2001 to K. Maxwell, discloses a rainwater run-off filtering system. The system includes a tank for holding and filtering run-off water. The tank is generally cylindrical with a horizontal axis. At least one manway allows for the introduction of water and a filter media. A horizontal grate is disposed at the bottom of the tank and supports a bed of gravel and sand. Incoming water is directed onto the sand bed so as to percolate through the sand to a space below the grate. The outflow of water from the tank is regulated by a baffle plate bounding the sand bed.
U.S. Pat. No. 7,258,785, issued on Aug. 21, 2007 to Weir et al., teaches a method and apparatus for separating oil and debris from urban water run-off. The apparatus is formed of a chamber which is mounted in a storm drain system and has an inner basin with a tilted wire wedge wire screen filter which is in the path of flow of the runoff, an organic absorber floating on the water as it collects in the basin, and a discharge plate having a series of holes that are sized to regulate the flow rate of discharge of the water from the basin for removal through an outlet at the lower end of the chamber.
U.S. Pat. No. 7,368,054, issued on May 6, 2008 to Porter et al., provides an apparatus to separate oil and debris from an aqueous fluid. The separator includes a container with a cover. The top portion of the container includes a control panel access door. The separator draws an aqueous fluid with one or more skimmers that float on the aqueous fluid inside one of a plurality of corresponding reservoirs. When the separator is operating, the surface portion of the aqueous fluid is drawn into each corresponding skimmer hose and transported to the separator by a pickup hose. The separator separates oil, debris and any sludge that may be in the aqueous fluid to provide a substantially filtered aqueous fluid.
U.S. Pat. No. 7,645,390, issued on Jan. 12, 2010 to S. McClanahan, provides a storm water drainage system capable of collecting, pretreating and disposing of the storm water runoff into a dry well. It serves to stop the flow of storm water into the dry well in the event hydrocarbons or other contaminants are present in the storm water.
It is an object of the present invention to provide an oil stop valve assemble that effectively restricts the flow of oil outwardly of a containment system.
It is another object of the present invention to provide an oil stop valve assembly that is inexpensive.
It is another object of the present invention to provide an oil stop valve assembly that avoids oil discharge.
It is a further object of the present invention to provide an oil stop valve assembly which effectively separates oil from the water.
It is further object of the present invention to provide an oil stop valve assembly which avoids any siphoning effects as a result of high flows through the outlet pipe.
It is a further object of the present invention to provide an oil stop valve assembly which avoids the effects of turbulence upon the valve assembly and, as such, avoids plugging.
It is still further object of the present invention provide an oil stop valve assembly in which the float of the valve can be easily changed, replaced or repaired.
It is still further object of the present invention provide an oil stop valve assembly which provides for easy inspection and cleaning.
It is still a further object of the present invention to provide an oil stop valve assembly which is easy to use, easy to manufacture and easy to repair.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.